The invention relates to a module for extracting samples in gas phase of compounds present in an underground working liquid. The invention also relates to an installation for analyzing gas samples and including such an extractor module.
U.S. Pat. No. 5,090,256 provides for an installation of this kind, in which the extractor module receives a drilling liquid from a pump fed from a head for taking liquid samples. The extractor module stirs the liquid to release the gases that are to be found therein. The released gases are collected from the extractor module for subsequent analysis in a device located downstream.
That extractor module presents the drawback of being capable of extracting only part of the gases contained in the liquid, and in particular it does not enable heavy hydrocarbons of C5 to C8 order to be extracted.
French patent document FR-A-2 799 790 provides a receptacle for extracting gas from liquid fed by a pump and evacuated by a delivery line. A pipe connects the receptacle to means for analyzing and measuring the extracted gas, and an inlet for a gas, air or inert gas, admits gas into the receptacle in order to adjust the gas entry flow rate.
That receptacle for extracting gas, and the installation in which it is provided, also present a certain number of drawbacks.
In practice, the gas inlet often becomes clogged, contrary to the looked-for effect.
It is necessary to cause a large volume of liquid to flow through the receptacle in order to extract a quantity of gas that is sufficient for analysis.
Finally, the large volume of liquid in the receptacle requires heater means to deliver a large amount of heat, consequently consuming a large amount of energy, whereas little electrical energy is available in the vicinity of the extractor module.
The invention seeks to obtain an extractor module and an installation including the extractor module that mitigate the drawbacks of the prior art.